This invention relates to improvements in container lids and, particularly, to lids for use with wide open-mouth containers. For example, the container lid of the present invention is useful particularly in connection with paint cans although it may be used in other environments where it is desired to securely cover a wide-mouth container having a lip extending about the periphery of the container.
Typically, paint cans are formed from suitable metal, usually steel, provided with a peripheral lip and a channel, both of which are intended to provide suitable seal with the usual metal lid. When the paint cans are sealed at the factory, the seal usually is satisfactory. However, the can usually is opened with a prying tool such as a screwdriver which often results in deformation of the can and/or lid in a manner which may disrupt the cooperative seal between the can and the metal lid. As a result, when the can is re-covered, it is not uncommon for the seal to be insufficient, which, in turn, results in hardening and/or evaporation of the paint or other material in the container. In addition, improper sealing of the lid which may result from deformation of the lid seal, can result in leaks.
The present invention provides an improved container lid which is molded in a single integral piece from a suitable plastic material. The lid includes a top wall and a sidewall which extends downwardly from the periphery of the top wall. The upper portion of the sidewall is relatively thin to define a stretchable, deformable web. The lower portion of the skirt defines a relatively thick band of the plastic material which is less deformable than the web. The inner surface of the sidewall, at the juncture of the web and the lower sidewall portion, defines a shoulder which is intended to engage the underside of the lip at the upper end of the container. When the lid is pressed onto the container, the lower portions of the sidewall stretch outwardly to accommodate the lip. When the lid is pressed fully to a seated configuration, the shoulder snaps beneath the container lip and the lower band maintains a constricting force which maintains the shoulder in engagement with the lip. The height of the web is such that the web is caused to stretch and deform into snug sealing conformity with the container lip as the lid is pressed into place.
When used in connection with a container having a channel, such as a paint can, the lid may be provided with a sealing band molded integrally with and extending downwardly from the underside of the top wall. In a further modification, the sidewall may be interrupted and a latch may span the interruption to enable a secondary mechanical constricting force to be applied to the lid sidewall.
It is among the objects of the invention to provide an improved lid for a wide, open-mouth container, such as a paint can.
Another object of the invention is to provide a molded, one-piece plastic lid which snap-fits onto the container and which has a stretchable portion which is stretched tightly against a region of the container mouth to affect the firm seal.
A further object of the invention is to provide a container lid of the type described which may be used and reused without destroying its sealing capabilities.